Two views of Bessler's wheel. Edge view at left. Face view at right. This wheel was about 12 feet in diameter.
1. Side face of wheel, covering of a light fabric.
2. Edge of wheel.
3. Axle.
4. Two supports for the axle. The top plates suggest attachment to a ceiling.
5. Not found in picture. (Maybe it was the secret that makes it work!)
6. Four "stampers" (move up and down to strike the box below).
7. Pegs on axle, to lift the stampers and release them.
8. Pendulum. One in front and one behind the wheel.
9. Linkage arm to drive the pendulum.
10. Linkage from axle to pendulum arm.
11. Weights on the ends of pendulum arms.
12. Pillars (to support the pendulum?)
13. Cross brace between pillars (?)
14. Peg to attach rope to axle.
15. Rope wrapped around axle.
16. Rope to lift weights.
17. Pulley attached to floor.
18. Rope (duplicate label?)
19. Wall, with open window.
20. Pulley outside window.
22. Weight being lifted.
23. Pulley support beam.
24 & 42. Brake lock attached to floor and wheel rim.
Bessler's drawings of his wheels are reasonably consistent with each other, and also consistent with eyewitness accounts. Certainly Bessler had no intention of giving away his secret in books, pamphlets or pictures, so this picture may have missing or incorrect details, and of course, whatever is inside the wheel is never shown. The scale of the size of parts may not be entirely consistent within the picture (even though a scale in els is shown at the bottom). Certain other details are a puzzlement.
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| The 12 foot diameter wheel lifting a weight, and the wheel with one of the pendulums. |
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Could enough energy have been stored within the wheel itself to account for the reported demonstrations of its power? Without knowing details of what was in the wheel, we do know that witnesses reported clanking and scraping sounds presumably from the eight 4 lb weights. We know the visible portion of the wheel was covered with opaque canvas fabric or oiled cloth, so no one could see the interior mechanism. We have reports that a man who tried to stop the wheel by grabbing it at the rim was lifted off his feet, but generally no demonstrations derived any force or work from the wheel itself, only from the wheel's axle.
So the visible impression the spectators got was of a massive 12 foot diameter wheel turning at 26 rev/min. Under load, it only slowed to 20 rev/min. That surely would seem impressive. How massive was the wheel? The contemporary documents don't tell us. One student of the Bessler story estimates 400 to 700 lb. Let's accept that as reasonable (for now) and see what we can conclude. We have no reason to suppose that anything but the wheel's outer shell rotated at that speed. Much of the weight inside the wheel may not have rotated at all. Surely the eight four pound weights were not the secret of the machine, for they could provide only 8 x 4 x 12 = 384 ft-lb of work even if they fell a distance of 12 feet, the diameter of the wheel. Lifting a 70 lb weight 40 feet requires 70 x 40 = 2800 ft-lb of work. These cylindrical weights could only have been a distraction, misdirection, to lead spectators to assume they were part of the secret of the wheels.
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| What people supposed might be in the wheel. An ancient idea. |
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Many witnesses agreed that the secret to the wheel's behavior must lie within the wheel itself. At this time many people were familiar with ideas for perpetual motion wheels, and many of these had moving weights inside. Of course, these generally could only manage less than a revoluution before stopping. Observers heard clanking sounds as the wheel turned, and Bessler sometimes removed and then replaced a 4 pound metal cylinder through a small hole in the wheel's fabric covering. He was encouraging the hypothesis that the wheel was driven by weights inside. But, as we have seen, this may have been misdirection, for eight 4 pound weights clearly could not supply the work done by the wheel.
Suppose that 600 lb of weight inside the wheel was arranged to fall slowly, giving up its potential energy as it fell a distance of, say, 6 ft. That would provide 3600 ft-lb, barely enough to do the lifting demo once, that is, if the box of bricks really weighed 70 lb. Unless one assumes a much greater weight inside the wheel (seemingly impossible), or "fake" lightweight bricks (the more likely hypothesis) it seems that falling weight alone does not account for the reported behavior of the wheel. Some other source of stored energy within the wheel and axle is required.
If the brick box weighed only 30 lb, it would require only 1200 ft-lb to raise it 40 ft. This would be well about a third of the maximum energy you could get from a falling weight inside the wheel. I find it curious that those who analyze the Bessler story have not questioned whether the fakery might be only partly in the wheel, but also in the carefully staged demonstrations of output work. In all the accounts we have no clear statement of how many assistants Bessler required for these demonstrations. We know he had at least one. But surely the task of removing the wheel from its supports and replacing it would require more than that. My suspicion is that they were carefully instructed, just as a stage magician's assistants are as much responsible for the success of an illusion as is the actor who pretends to be a magician.
When the wheel was not lifting or doing other forms of work, the stored energy in the pendulums could maintain its motion for quite a while without drawing much energy from falling weight inside. The only energy loss would be due to bearing friction. The rate of fall of such a hypothetical weight could be varied, depending upon the work being done by the wheel. If no work was being done, the wheel presumably could turn for a very long time. The mechanism to accomplish that may have been the most important and ingenious secret Bessler wanted to keep.
Another speculation is that the wheel, or its rather unusually thick and long axle, contained a very tightly coiled spring to store energy for later release. The only suggestive piece of evidence is that Bessler was once "observed" to be making an adjustment through an opening in the canvas cover of the wheel and seemed to be "tightening" something. He certainly couldn't have been "winding" a spring by manpower to store 3600 ft-lb of energy! This observation could have other explanations and I don't give it much weight. But the possibility of a spring being wound prior to a public demonstration cannot be ruled out.
I do not rule out the wound spring hypothesis entirely, even though Bessler swore his wheel did not use "clockwork", falling weights, or springs. We have only his word on that. In the demonstration at Kassel, where one of his large wheels ran 42 days supposedly without slowing, clockwork and a wound spring could easily accomplish that and even longer, assuming that it only had to rotate the lightweight outer frame of the wheel. This wheel was not required to do work or lifting demonstrations. If those demonstrations requiring work were accomplished with slowly falling weight inside the wheel, those weights could easily have been disabled (or not present at all) in the Kassel demonstration. No one saw the interior of that wheel.
I haven't read everything relating to Bessler. But I wish some Bessler scholars would clear up some points for me.
Those who wish to understand the methods of deception used in the 18th century would do well to look into the famous case of The Turk, a chess-playing automata constructed and exhibted in 1770 by the Austrian-Hungarian baron Wolfgang von Kempelen (1734–1804). It purported to be a machine designed to imitate a living being—an automaton. Automata were popular entertainment all over Europe in the 18th century, and exhibited a high degree of skill in construction. The Turk was an oriental figure seated before a chessboard on a cabinet in front of him. Doors in the cabinet were opened to reveal complex clockwork inside. The clockwork was wound up, and the Turk would play a game of chess with a human opponent, often winning. It was a hoax, for the cabinet, which observers swore they had seen to contain only clockwork, actually concealed a person, who manipulated the Turk from within. (The two cabinet doors were not opened simultaneously, so the hidden person had time to move out of sight behind the closed door, a very simple deception common in the large illusions of stage magicians.) I mention this example to remind readers that this century had an abundance of mechanical ingenuity sometimes combined with deception. I am not suggesting that any of Bessler's demonstrations were done with a person inside the wheels. Their thickness would not accomodate even a small person. We should also remember that the 18th century was a time of notorious financial scams, which took in many gullible people and even entire governments. The "South Sea Bubble" and "Tulipmania" are well known examples.
Bessler's 11 foot diameter wheel was demonstrated to 12 dignitaries on October 31, 1715. They signed, attesting to, a document that has considerable detail. This is worth quoting because the details sound more imressive than those in accounts of other demonstrations of Bessler. But still there are many details inquiring minds want to know, that this document says nothing about.
The inventor first put in motion his six ells (~11 feet) in diameter and one foot thick machine which was still resting on the same wooden support upon which it had previously been mounted. It was stopped and restarted, turned left and right as many times as was requested by the commissaries or the spectators. The machine was started by a very light push with just two fingers and accelerated as one of the weights, hidden inside, began to fall. Gradually, within about one revolution, the machine acquired a powerful and even rotation, which continued until it was forcefully brought to a stop again; the machine preserved the same rapid motion when lifting a box filled with six whole bricks weighing together about 70 pounds. The weight was lifted by means of a rope conducted through a window by means of a pulley. The box was lifted as many times as was requested.This is one of the more complete attested accounts by witnesses. At first reading it sounds impressive in that many details are given. Yet it is frustrating in what it does not tell us.Furthermore the inventor, Orffyreus, in the presence of all, lifted the machine described above from its original wooden support. The timber posts were carefully examined from both top and bottom, as well as in the middle, particularly where a small cut was noticed. The same careful examination was devoted to the trunnions, the shaft, and to the bearings. During the inspection, not the slightest indication of imposture or deceit was found, rather everything was found to be right, complete, and without fault.
As further proof of its internal or inherent motive power, the machine was translocated to another support in such a way that the trunnions on both sides of the axle were laid uncovered in the open sockets. The whole assembly could see over and under, and both sides of the machine; and all present were invited to inspect the bearings, but no holes were found. All present examined them with their eyes, but no sign of fraud was seen. It was possible to translocate the machine and turn it left and right as many times as was asked by the respectable Commission. The machine regained its strong, fast, even rotation each time. The movement was accompanied by quite a loud noise that lasted until the machine was brought to a forced stop. Thus nothing suspicious happened.
Finally, it should be noted that right at the start, before the machine was subject to any testing, all rooms above, below, and on either side were examined by the Commission. It was also verified that the stamps were not hollow, and no indication of any mechanism moved by a cord was found.
All that has been written above is the truth, and has been acknowledged by signatures in our own hand without any reservations... signed at Merseberg, 31st October, year 1715.
One mistake that we should not make is to assume that all of Bessler's wheels, and the various demonstrations of them, used the very same methods of deception. Some things the smaller wheels could do may not have been done by the larger wheels in the same way. The wheel that "ran two months" in a sealed castle room was apparently never used to lift weights or do other forms of work. The earler demonstrations ran for short periods (how long, the accounts don't say). But no wheel was reported to run for two months and do the demonstrations of lifting. So the two types may well have operated by different methods. Indeed many critics observed that the long-running wheel could easily have run by clockwork and a wound spring, even for much longer periods of time, since it was expending no energy other than that lost to friction. Nor should we assume that this wheel weighed as much as the others, for it could easily have been only a lightweight shell, not required to do any heavy lifting.
We should not speak of Bessler's "wheel" but of Bessler's "wheels", for they may have been quite different in internal mechanisms, not only different in size. To use the singular suggests that they all operated on the same principles.
What accounted for the wheel's weight? The visible portion was opaque canvas, oil-cloth or waxed linen on a lightweight wooden frame. We might generously assume the frame and axle accounted for 100 pounds. On at least one occasion a cylindrical metal weight was brought out from inside the wheel which an observer estimated to weigh four pounds. When the wheel rotated, eight "clunks" were heard per revolutions, leading viewers to assume there were eight such weights inside, though only one had been seen. That's 64 pounds.
While eyewitness accounts give many other details, they are silent about the wheels' weight, or how that weight was measured. Why didn't they consider it important? You'd think they might at least mention how many men were required to lift it. It's an example of the fact that the witnesses, even those with scientific background, weren't considering the matter in a quantitative way. Even 's Gravensande, who did some calculations, first made the common (at the time) error of using mv for energy, rather than the correct mv2/2, an error he acknowledged later.
In the document above I've mentioned some of the problems with this story, and some of the hypotheses I've seen proposed. I am not saying that I accept any of these hypotheses. Many require assumptions for which we have no historical evidence, and probably never will have. But I see nothing in the accounts to suggest that anything magical, or even anything beyond presently known physical laws, was going on.
People ask me why I find this historical cold-case somewhat interesting, supposing that I might harbor the suspicion that Bessler's wheels really violated physical laws. Not at all. I have long been interested in conmen who cleverly deceive people: artists who fool the experts with forged paintings, writers who invent hoaxes. They serve a valuable social purpose, teaching us to look behind appearances, mistrust our emotions, hopes and beliefs, and to recognize what's possible and what isn't. Anyone who could fool people not only in his lifetime, but centuries after his death, as Bessler did, certainly deserves recognition.
Return to perpetual futility.